Wednesday, December 20th, 2017, 16:10

Schreiber 309

Yael Golan, TAU

Abstract:

Many communication networks exist around the world. Many of our
daily activities are based on them, from talking on the phone, watching
television, all the way to surfing the Internet. A wired network can be
modeled as a graph. The stations, or switchboards, are the graph
vertices, and the wires that connect the stations are the edges. A wired
network can be damaged by extreme weather conditions (like wind storms,
hailstones, etc.), or by a bomb, during a war, or by other means of
attack, such as an electro-magnetic pulse (EMP).

In
this lecture we consider communication networks as straight-edge graphs
embedded in the plane, and an attack on the network as a region that
destroys all the edges that intersect it. We want to find the placement
of an attack of some given shape where it intersects the maximum number
of edges of the graph.

We review several
combinations of different types of graphs and attacks. Three of the
problems that are discussed were already solved in "Assessing the
vulnerability of the fiber infrastructure to disasters" by S. Neumayer,
G. Zussman, R. Cohen, and E. Modiano. All of our algorithms
significantly improve the results of this preceding work.